Hypodermic syringe.



No. 836,367. PATENTED NOV. 20, 1906. 1

H.. J. DETMERS HYPODERMIO SYRINGE.

AIPLIGATIOR FILED DOT. 2, 1905.

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UNITED STATES PATENT OFFICE.

HENRY J. DETMERS, OF COLUMBUS, OHIO.

HYPODERMIC SYRINGE.

Specification of Letters Patent.

Patented Nov. 20,1906.

Application filed October 2, 1905. Serial No. 280.877.

provements in hypodermic syringes,and has particular relation to thecoupling between the parts.

It is a well-known fact that more or less difficulty has beenencountered in the con struction of hypodermic syringes to obtain orproduce air and water tight joints, and while air and water tight jointshave been made the result has generally been a complicated structure orone requiring expert mechanical skill to manufacture. It is also a knownfact that air and water tight joints may be had if the contactingsurfaces of the oint are properly made to erfectly fit.

It is there 'ore the object of my invention to provide a syringe inwhich air and water tight joints may be had between the barrel and thecap or adapter and also between the cap and the hub of the needle ornozzle, the said joints being obtained without the use of washers orpacking, but by the arrangement and construction of the parts, as willbe here inafter more fully described and pointed out.

With the above and other objects in View the invention consists of thenovel details of construction and operation, a preferable embodiment ofwhich is described in the specification and illustrated in theaccompanying drawings, wherein I Figure 1 is a partial longitudinalsectional view of my improved syringe, the plunger and a portion of thebarrel being omitted. Fig. 2 is a similar view, a portion of the barreland the nipple of the cap being shown in elevation.

In the drawings the numeral 1 designates the barrel or cylinder, whichmay be formed of metal or any other suitable material. The usual plungerwhich operates in the barrel has been omitted for the sake of clearness,as it is not needed for a full understanding of the invention. The lowerend of the barrel 1. is tapered to a knife-e.d.ge, so as to produce anouter conical surface 2, which is surmounted by peripheral screw-threads3. The reduced or conical end of the barrel is adapted to be received inthe socket portion of a cap or adapter 4., which is provided with anupwardly-tapered or conical surface 5, conforming to the conicalsurface2,and provided with internal screw-threads 5, so that when thecap is screwed into position, the threads 5 engaging the threads 3, theconical surfaces will be drawn into close contact and an air and watertight joint provided. It will be understood that the conical portions 2and 5 may be so proportioned that as the cap is drawn onto the barrel bythe engagement of the screw-threads the conical end of the barrel willbe wedged therein, producing a oint between the contacting surfaceswhich will be absolutely air and water tight. The cap is formed with anipple 6, which terminates in a cone-shaped portion 7. A passage 8 eX-tends through the nipple and communicates centrally with the bore of thebarrel 1. Peripheral screw-threads 9 are formed on the nipple adjacentthe cap and extend to the coneshaped portion 7. A needle or nozzle 10 isformed with a hub portion 11, which is provided with internalscrew-threads 12, adapted to be received by the threads 9, and a conicalbore 14, conforming to the contour of the cone-shaped body 7. The sameprinciple is herein carried out as is observed 1n the joint between thebarrel and the cap, the coneshaped portion 7 fitting snugly within theconical bore or recess 14 of thenozzle and the surfaces of the partsbeing drawn into close relation when the screw-threads are engaged. andthe hub drawn onto the nipple. The cone-shaped portion 7 also runs to aknife edge, so that a smooth and continuous joint is produced and thepassage 8 allowed to regs ister with the bore of the nozzle or needle.

Although air and water tight joints are had and the parts drawn intosuch close relation as to actually bind on each other, it will beobvious that either the cap or the nozzle may be readily removed andaccess had to the parts for the purpose of cleansing and inspecting.

I wish it understood that while I have described the joint between thehub of the nozzle and the nipple as applied to hypodermic and othersyringes the same may be employed in connection with other deviceswherein it is desirable to produce water and air tight joints betweenthe nozzle and the part to which it is connected. I also desire to callattention to the fact that the inner horizontal surface 4? is perfectlyflat and at substantially right angles to the sides of the barrel. Thisaffords a better joint and obviates all recesses or depressions in whichdirt and bacteria may collect, and when a fiat-ended plunger is. usedthe drawing of airbubbles is prevented. It is further to be noted thatthe passage 8 has substantially the same diameter as the needle ornozzle 10 and the outlet formed by the passage and the needle is smoothand continuous and without recesses or enlargements. This isaccomplished by tapering the conical portion 7 to practically aknife-edge. These features lend materially to the production of ahighly-antiseptic syringe.

Having now. fully described my invention, what I claim, and desire tosecure by Letters Patent, is

1. In a hypodermic syringe, the combination with a barrel comprising anopen-ended tube, the wall of the lower ortion of which tapers in suchmanner as to orm a knife-edge at the bottom of said tube, of a capadapted to be screwed upon said tube and having a flat-bottomed recessformed therein, theinner wall of said recess conforming to the taperedportion of the tube and the knife-edge contacting with the flat bottomof said recess when the parts are assembled, a nozzle carried by saidcap, said cap and saidnozzle having openings formed therethrough whichregister with each other.

2. In a hypodermic syringe, the combinaportion of its length, theknife-edge formed at the bottom of said tube contacting with the flatbottom of the recess of the cap when the parts are in their assembledposition, a nipple projecting from said cap and having a taperingportion, said nipple and cap having an opening formed therethrou gh, the juncture of the wall of said opening and the tapering wall of thenipple forming a knife-edge, and a nozzle having threaded engagementwith a .portion of said nipple and having a conical bore adapted toreceive the tapering portion of the nipple, said nozzle having anopening formed therethrough which registers with the opening formedthrough the nipple and cap.

In testimony whereof I affix my signature in presence of two witnesses.

HENRY J. DETMERS.

Witnesses A. L. PHELPS, M. B. SoHLEY.

